Thermo-mechanical and electrical properties of graphene nanoplatelets reinforced recycled polypropylene nanocomposites

Abstract

This study investigates the thermo-mechanical properties of graphene nanoplatelet (GNP)-filled recycled polypropylene (rPP) nanocomposites to enhance their performance and sustainability. It examines the influence of GNP loading on mechanical, thermal, and electrical behavior, focusing on tensile strength, Young's modulus, impact strength, heat deflection temperature, thermal conductivity, and electrical resistivity. The GNP-rPP composites are fabricated by functionalizing GNPs through mild acid treatment to enhance compatibility with the rPP matrix, followed by melt mixing in a twin-screw extruder at varying GNP loadings (0–20 Phr). The tensile strength, Young's modulus, and flexural strength of recycled polypropylene increased by 15.6 MPa, 3.7 MPa, and 2.41 MPa, respectively, as the GNP loading increased from 0 to 20 Phr. Adding Adding GNP up to 20 Phr into the rPP matrix also increased the crystallization, melting, onset, and maximum decomposition temperatures by 5, 4.7, 8.36, and 7.02 °C, respectively. Additionally, the thermal conductivity shows an increasing trend, with an improvement of 221 mW/mK. However, including fillers reduced electrical resistivity by 105 Ω cm and impact strength by 64.27 Jm⁻1. The significance of this work lies in providing eco-friendly alternatives to conventional polymers, promoting the adoption of recycled materials, and contributing to sustainable product design. The outcomes offer valuable insights for industries promoting a circular economy with cleaner production while reducing the carbon footprint. Also, the recycling and reuse of synthetic polymers uncover a valuable prospect for tackling the escalating global polymeric waste problem.